Railway traffic controlling apparatus



Oct. 18, 1938. R. A. M CANN ET AL 2,133,627

RAILWAY TRAFFIC CONTROLLING APPARATUS I Filed July 8, 1956 5 Sheets-Sheet 2 INVENTORS y S. Ybung and A.M C 12.

A JT

Hem" 1301? 1 9 10. 5y

THEIR ATTORNEY 1 v r 5 6A9]? 9'18 Patented Oct. 18, 1938 UNITED STATES PATENT OFFICE RAILWAY TRAFFIC CONTROLLING APPA- Young, Wilkinsburg,

Pa., assignors to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application July 8, 1936, Serial No. 89,602

23 Claims.

Our invention relates to railway traffic controlling apparatus, and more particularly to apparatus for governing the movement of trafiic through a track layout including a plurality of track switches which may be arranged to form difierent trafic routes.

One object of our invention is the provision of means for electrically interlocking the switches and signals in such a manner that the operations of setting up the different trafiic routes may be controlled electrically by momentary current impulses produced either by the operation of push buttons or levers or by the transmission of code signals from a remote point. Our apparatus is particularly adapted for use in a centralized traffie control system, and is an improvement upon that disclosed in a pending application for Multiple control apparatus, Serial No. 379,163, filed July 18, 1929,. by Charles A. Brooks. A further object of our invention is the provision of a system of route control whereby a plurality of switches may be arranged to set up a route and a signal governing traflic over the route may be cleared in one operation.

In practice, it is usually the case that a large majority of the .trains which pass through a track layout such as is herein disclosed are main line trains, and that switching operations are relatively infrequent. In more complicated layouts this situation is emphasized because the number of possible routes is greatly increased, and the use of a majority of these may be extremely infrequent. If this is the case, there is little to be gained, from the standpoint of facilitating operation, in providing route control for such infrequently used routes, while on the other hand, the manipulation of the apparatus may be simplified by the provision of route control for those routes which are the most used, and for which it possesses important advantages in facilitating traflic and in minimizing the number of operations and delay in setting up routes and clearing signals for approaching trains. Furthermore, in any case the provision of facilities for the individual control of the switches may be desired for the reason that it enables trouble with an individual switch of a route to be quickly located. A feature of the present invention resides in an arrangement of apparatus such that both route and function control as above described may be employed in the same plant so as to simplify both the apparatus and its manipulation to the maximum extent.

We will describe three forms of apparatus embodying our invention, and will then point out the novel features thereof in claims.

Referring to the accompanying drawings, Figs. 1A, 1B, and 1C illustrate one form of our apparatus, in which Fig. 1A illustrates the control panel situated at the point of control and includes a miniature representation of the track layout to be controlled together with the control push buttons and suitable indication devices. Fig. 1B shows the switch and signal and route control relays controlled directly by the push buttons of Fig. 1A, while Fig. 1C shows the track layout and the interlocked circuits for controlling the switches and signals thereof in response to the operation of the control relays of Fig. 13. Fig. 2 shows the control relays of Fig. 1B arranged for control by code signals. This view, when taken with Fig. 1C, illustrates the second form of our apparatus in which the switches and signals are governed by the operation of code signaling apparatus. Fig. 3 shows a modification of a portion of Fig. 2 whereby the control relays are actuated directly by push buttons as in the first form of the apparatus; but in accordance with the positions of interposed switch and signal levers.

Similar reference characters refer to similar parts in each of the several views.

Referring to Fig. 10, the track diagram shown therein represents the track rails of each of the two main tracks of a double track railway connected by a crossover comprising the switches 3 and 3A, the lower track being also connected to a siding by a single switch l. While a specific track layout is disclosed, it is to be understood that the apparatus of our invention is adapted to control other track layouts that may involve entirely different combinations of switches and signals, a layout including but one crossover and but one single switch having been chosen to illustrate the principles of our invention for simplicity. An indicated in the drawings,the tracks are divided into sections by insulated joints, and the detector track sections including the track switches are identified by the references IT and 3T, respectively, while the adjoining approach track sections are indicated by the references 2T, A2T, 4T, and Ad'I, respectively. Each track section is provided with the usual closed track circuit including a battery 5 and a normally energized track relay in accordance with standard practice, and each track relay is identifiedby the reference letter TR with a numerical prefix designating the track section to which it corresponds. The track relays ITR and 3TB each have a slow pickup slow release repeating relay '1? associated therewith, as shown. The movement of trafiic over the switches is governed by the signals bearing the references 2 and 4, with distinguishing prefixes R and L indicating the direction of traffic governed by the signals.

In order to simplify the drawings and to enable the circuits to be more readily traced, we have identified each relay contact by a number and each relay by a letter with distinguishing prefix or suifix including a number identifying the switch or signal with which the relay is associated, those contacts not adjacent the respective relays which operate them bearing the reference characters for the respective relays as well as numbers identifying the contacts. Furthermore, instead of showing the sources of current for energizing the relays and the wires leading thereto in detail, we have shown only the terminals of the sources, which we have designated by the reference characters B and N referring to the positive and negative supply terminals, respectively, and by the reference character C, referring to the return or common terminals. Thus, referring to Fig. 10, the circuit for relay ITP, for example, may be traced from one terminal B of a source of current, front contact 6 of track relay ITR, relay ITP, to the other terminal C of the same source, this circuit being opened when relay lTR is shunted due to the occupancy of section IT by a train.

Referring now to Fig. 1A, it will be seen that the track diagram comprises a miniature representation of the track layout of Fig. 1C, and that it includes the usual track indication lamps each of which bears the reference character E with a prefix identifying the track section to which it corresponds. The push buttons for controlling the switches and signals individually are arranged in groups in a row below the diagram. Each group of control buttons takes the place of the usual control lever such as is illustrated for example in the left-hand portion of Fig. 2, and it is to be understood that the operation of each control button corresponds in function to the movement of a control lever to a corresponding position. Directly above the control buttons are corresponding groups of indication lamps, which may be controlled in a Well-known manner so as to indicate to the operator the condition of the switches and signals of Fig. 10. As herein disclosed, the apparatus is so arranged that the main line signals RA2 and LA4 cannot be cleared by the operation of the signal control buttons located below the diagram, the clearing of these signals being effected by the operation of special route control buttons R2 and L4P, respectively, which are located in the track diagram at the entrance to the main line routes b-e and H, which these signals govern. A single operation of a route button serves to operate the track switches to set up the corresponding main line route and to then clear the signal RZA or L4A to permit a train to pass over the route, provided conditions are proper so that the switches are free to be operated as indicated by the lighting of. the route lamp R2E or L4E adjacent the route button. Each route button also has associated with it a callon button 2U or 4U, which may be operated to admit a train at slow speed to a route already occupied by a preceding train, in accordance with the usual practice.

Fig. 13 illustrates the circuits which are con trolled directly by the push buttons of Fig. 1A and includes normal and reverse switch stick relays NWS and RWS controlled by the switch control buttons N and R, signal stick relays LHS and RHS controlled by the signal control buttons L and R for clearing the signals, call-on stick relays US controlled by the call-on buttons U, and route stick relays RS controlled by the route buttons P. In addition, a normal signal control button N is provided for each group of signals for releasing the relays HS, RS, and US to put the cleared signal to stop. The circuits for the stick relays of Fig. 1B are also governed l by the apparatus of Fig. 1C, and further consideration of these circuitsq will therefore be deferred until after this apparatus has been explained in detail.

Referring to Fig. 10, the single switch I is actuated by a power-operated switch machine ISM of any suitable type, such, for example as the one disclosed in the Zabel Patents Nos. 1,293,290 and 1,413,820, and the crossover switches 3 and 3A are actuated by similar switch machines 38M and 3ASM. Each switch machine SM is provided with the usual motor having its operating circuits controlled by the contacts of a polarized switch control relay WR in the manner disclosed in the Willard Patent No. 1,380,452, as indicated diagrammatically by dotted line connections in the drawings, so that the switch or switches will be operated to normal or reverse, when the control relay WR is energized and its polar contacts are closed to the left or right, respectively. Each relay WR is controlled by the manually governed switch stick relays NWS and RWS of Fig. 1B and by a switch locking relay MP. The locking relays MP are controlled in turn by the track relays TR and their repeaters TP for the respective switch sections, and by approach locking relays LMR and RMR. which are controlled by the signals. Relay IWR is also controlled by a section locking relay IWS.

Each switch machine is provided with the usual circuit controller, as disclosed in the Zabel patents hereinbefore referred to, for controlling a polarized indication relay KR, as indicated diagrammatically by dotted line connections in the drawings. For an understanding of the present invention it will suffice to point out that when switch machines 38M and 3ASM are locked normal or reverse, relay SKR will be energized with its polar contacts closed to the left or right, respectively, and that relay IKR is similarly controlled by switch machine ISM. Each relay KR. is provided with a pair of repeating relays NKP and RKP each of which is energized only when the polarized relay KR is energized in a position corresponding to that of the associated switch control relay WR. Thus the circuit for the normal repeater INKP for switch I may be traced from terminal B, neutral contact [4 and left-hand polar contact 15 of relay IKR, relay INKP, lefthand polar contact l6 and neutral contact I! of relay IWR to terminal C. The circuits for the reverse switch repeater IRKP and for the corresponding relays 3NKP and 3RKP for the crossover are similar and may be readily traced from the drawings.

The circuit for the locking relay 2MP may be traced from terminal B, front contacts l8 and I9 of the approach locking relays RZMR and LZMR controlled by signals 2, contacts 20 and 2| of relays !TP and lTR, contact 22 of relay IWS, relay 2MP to terminal C, while the circuit for relay 4MP may be traced from terminal B, contacts l8, I9, 20, and 2|, front contacts 23 and 24 of track relay 3TR and its repeater 3TP, front contacts 25 and 26 of the approach locking relays IAMR and RAMR controlled by signals 4, relay 4MP to terminal C. The section locking relay IWS has a pickup circuit which may be traced from terminal B, front contacts 2'! and 28 of relays 3NKR and 3TB, relay lWS to terminal C and a stick circuit including contact 3E? and its own front contact 29. As hereinafter explained, each approach locking relay such as relay LQMR, is controlled by the associated signals in such a manner that it will become released when the signal, in this case, signal LA4 or LE4, is cleared. Relay LGMR has a front contact 36 bridging contact 21 in the circuits for relay lWS, and it follows that if the route 11-47 or dC has been set up, contact 27 will be open and if signal LB4 is cleared, contact 36 will open to release relay lWS to open contact 22 in the circuit for relay 2MP, so as to lock switch I, but switch I is not locked if route d a is set up and signal LA! is cleared because in this case contact 2'! will be closed.

The switch control relay IWR has a normal control circuit which may be traced from terminal B, front contact 3! and back contact 32 of the switch control relays INWS and IRWS, front contact 33 of relay 2MP, relay IW'R to terminal C, and a reverse control circuit which extends from terminal N over back contact 34 and front contact 32 of relays INWS and IRWS, contact 33, relay IWR to terminal 0, so that relay IWR may be operated to normal by energizing relay lNWS, or to reverse by energizing relay IRWS, provided relay 2 MP is energized. It will be apparent from the foregoing that relay 2MP can be energized only when conditions are favorable for operating switch 1, namely, when signals 2 are at stop and section IT is unoccupied, and that if the crossover is reversed signal L134 which then governs movements in one direction over switch i must also be at stop.

When the switch completes its movement in response to an operation of relay IWR, relay iKR will become energized in a corresponding direction, and if a signal is then cleared to release relay ZMP and to thereby lock switch 5, relay IWR. will remain energized due to the closing of a holding circuit which may be traced from terminal B or N as the case may be, contacts 35 and 36 of relay lKR, back contact 33 of relay 2MP, relay lWR to terminal C, thereby holding the switch in-its last-operated position as long as relay 2MP is deenergized.

The crossover control relay 3WR is similarly controlled by the switch control relays SNWS and 3RWS and by the locking relay 4MP, and it will be apparent from the drawings that relay ilViP will be energized to permit operation of switches 3 and 3A only when all the signals 2 and 4 are at stop and sections IT and ST are both unoccupied.

The signals shown in Fig. 10 may be of any suitable type and in practice these signals governing high speed routes will generally be threeposition signals governed in accordance with the condition of other signals in advance, not shown herein, in addition to being subject to manual and track circuit control. To illustrate the present invention, however, it is deemed sufficient to assume merely that each signal indicates proceed when energized and indicates stop when deenergized. A signal relay H is provided for each signal arm, and each signal relay H controls one or more circuits for the signal as indicated diagrammatically by dotted line connections from the contacts of the relays H to the signals of the track diagram.

The circuits for the approach locking relays LMR and RMR will in practice generally include time or approach. locking features which not being part of the present invention have been omitted to simplify the drawings, and these relays may be arranged for example, as disclosed in Patent No. 2,046,049, for Railway traffic controlling apparatus, granted June 30, 1936, to Earl M. Allen. To illustrate the present invention, it is deemed sufiicient to point out that each relay MR. is energized only when the signals which control it are at stop. Thus, in the lower portion of Fig. 1C, a circuit for relay RZMR is indicated as extending from terminal B over back contacts 37, 38, and 39 of the signal relays RAZH, RBZH, and RCZH for the three signals R2, through relay RZLAR to terminal C, a portion of this circuit being shown dotted to indicate the omission of the approach or time control. The circuits of the remaining approach locking relays MR are generally similar and will be readily understood from the drawings. A transverse arrow has been added to each of the front contacts of the MR relays to indicate that these contacts are slow to close, but it is to be understood that in accordance with usual practice the delay in the energization of these relays is nullified when. a signal is put to stop automatically by a train and also when it is put to stop manually and the approach section is unoccupied.

The signal relays H are controlled over the signal relay network shown in the lower portion of Fig. 1C, the circuit for each signal relay H being controlled by front contacts of a signal control relay HS or a route relay RS for the corresponding signal or route and by a back contac of a signal control relay HS or route relay R6 for an opposing signal. Disregarding the branch circuits controlled by the call-on stick relays US, it will be seen that signal relay network is a counterpart of the track layout and includes a circuit for each direction for each route through the layout, each circuit being formed by con ductors corresponding to portions of the track which are connected together by indication relay contacts controlled in accordance with the positions of the track switches. The route circuit for each signal is connected to terminal B of the source of current over a front contact of the approach locking relay MR associated with the opposing signal, thereby not only insuring that a signal cannot be cleared unless the opposing signal indicates stop, but also interposing a time delay in the reversal of the direction of traffic when this feature is embodied in the cir cuits for the relays MR.

Assuming that switches I, 3, and 3A are normal and sections IT and 3T unoccupied, if relay RZRS is picked up and relay LZHS is released, relay RAZH will be energized over a circuit from terminal B, contact 40 of relay LZMR, back contact M of relay L2HS, front contacts 42, 43, and 44 of relays SNKP, IKR, and RZRS, back contact 45 of relay ZUS, front contacts 46 and M of relays BNKP and INKB, front contacts 48 and 49 of the track relays ITR and 2TB, relay RAZI-I, back contact 50 of relay IRKP, and front contact of relay RZRS to terminal C. It followsthat the high speed signal RA2 will be cleared for a train movement from left to right over the lower main track in response to the energization of the route relay RZRS when the route be is set up provided signal L2 is at stop and sections 4 T 1 signal LA4 for a train movement from right to left over the upper main track in response to the energization of the route relay L4RS when the route da is set up, provided signal R4 is at stop and sections 3T and 4T unoccupied. This will be apparent from the drawings, since the circuit for relay LA4H is similar to that just traced except that it is not controlled by switch I.

If now the call-on stick relay 2US is energized, relay RA2I-I will be deenergized and a branch of its control circuit will be completed over front contacts 52 and 53 of relays 3NKP and INKP, through relay RBZH and back contact 54 of relay RAZH. It is evident, therefore, that after relay RZRS has been energized and route b-e has been set up, relay RB2H may be energized to clear the slow speed signal RB2 to permit a train to enter route be, even though section IT or 2T is occupied and contact 48 or 49 is open. The call-on stick relay 4138 may likewise be perated to energize relay LB4H for clearing signal LB4 under corresponding conditions to permit a slow speed movement over route da.

Assuming switch I reversed and switches 3 and 3A normal, if relay REHS is energized, a circuit may be closed from terminal B, front contact 40 of relay LEMR, back contact II of relay L2HS, front contacts 42 and 43 of relays 3NKP and EKR, back contact 44 of relay R2RS, front con tacts -6 and 64 of relays R2HS and IRKP, relay RCZI-I, front contacts 50 and 63 of relays IRKP and R2HS to terminal C. Relay RC2H may therefore be energized in response to the energizaticn of relay RZHS to clear signal RC2, provided route ee is set up and signal L2 is at stop. Assuming switches 3 and 3A normal, if relay L2HS is energized, a circuit may be closed from terminal B, front contact 55 of relay R2MR, back contacts 56 and 44 of relays R2HS and RBRS, front contacts 43, 42, and 4| of relays iKR, 3NKP, and LZHS, relay L2H, front contact 5% of relay L2HS to terminal C. Relay L2H may therefore be energized in response to the energization of relay L2HS to clear signal L2, provided either route eb or ec is set up and signals R52, RBZ, and RC2 are at stop. Similarly, relay R lH may be energized in response to the energization of relay R4HS to clear signal R4 under corresponding conditions to permit a slow speed movement over route ad, as will be apparent from the drawings.

Assuming that switch I is normal and switche and 3A are reversed and that relays RZHS is nergized, a circuit will be closed from terminal B, front contact 58 of relay L4MR, back contacts 59 and 60 of relays L4HSand L4RS, front contacts 6i and C3 of relays 3RKP and IKR, back contact a". of relay R2RS, front contacts 56, 62, and 53 of relays R2HS, ZIRKP, and INKP, relay R325, back contacts 54 and 50 of relays RA2H IRKP, front contact 63 of relay RZHS to terminal C, so that relay RB2H will be energized to clear signal RBZ in response to the energization of relay RZHS when route b.-d is set up and signals LA and LB4 are at stop. If switch I is reversed, contact 53 in the circuit just traced will be open and this contact and relay RBZH will be shunted by a branch including front contacts 64 and of relay IRKP and the winding of relay RC2H. It follows therefore that relay RC2I-I will be energized to clear signal RC2 in response to the energization of relay RZHS when route c-d is set up and signals LA4 and LB4 are at stop. The circuit for the corresponding opposing signal relay LB4H includes front contact 43 of relay IKR which is closed in both the normal and reverse positions of switch I but is otherwise similar to the circuit just traced and it is evident that relay L4BH will be energized to clear signal L4B in response to the energization of relay L4HS when either route db or (1-0 is set up, provided the signals R2 are at stop.

Having now explained in detail how the apparatus of Fig. 1C is controlled by the stick relays of Fig. 1B, we will next point out how these relays are controlled.

Referring to Fig. 1B, and assuming that relay RZRS is deenergized and that conditions are proper for operating switch I so that relay 2MP is energized as already described, it is apparent that relay INWS may be energized by the momentary operation of push button IN and that relay IRWS may be energized by the momentary operation of push button IR, and that each of these relays when energized releases the other to complete its own stick circuit. Thus for example, the operation of push button IR completes a circuit from terminal B, contacts 66 and 65, relay IRWS to terminal C, whereupon relay lRWS picks up, opening contact 61 to release relay INWS to complete the stick circuit for relay IRWS over contacts 68 and 69. It is also apparent that relays 3NWS and 3RWS are similarly controlled by push buttons 3N and 3R.

The circuits for the signal stick relays LHS and RHS are arranged to prevent their energization unless the approach locking relays associated with conflicting or opposing signals are energized, and also when the routes governed by the stick relays are not available. The signal stick relays and also the route relays RS are released manually only by the operation of a signal stop key N, so that when a signal has been cleared it cannot be put to stop or otherwise interfered with by the operation of any push button L or R governing another signal. Thus, for example, relay LZHS has a pickup circuit extending from terminal B over push button 2L, front contacts II and I2 of relays RZMR and 3NWS, relay L2HS, back contacts I3 and 70 of relays R2HS and R2RS, push botton 2N to terminal C, and when relay LZHS becomes energized it opens contacts I4 and I5 in the circuits for relays RZHS and R2RS, respectively.

The pickup circuit for the signal stick relay L4HS is arranged somewhat differently. When the crossover is normal, its pickup circuit includes contacts 84 and 93 of relays 3NKP and R4MR and can be closed only when signal R4 is at stop, but if the crossover is reversed, contact 84 will be opened and the circuit will then include contact 83 of relay R2MR so that it can be closed only when the opposing signals R2- are at stop. The circuits for relays R4HS and RZI-IS are similar to those for relays L2HS and L4HS, respectively, as is apparent from the drawings.

The route stick relays RS not only control the signals, as already explained, but also govern the switch stick relays controlling the switches for their respective routes. For example, relay RZRS controls front contacts I6 and 11 in the circuits for relays INWS and 3NWS and back contacts 66 and I8 in the circuits IRWS and 3RWS. The switches I, 3, and 3A are therefore operated to normal by the energization of relay RZRS and are held normal as long as relay RZRS is energized, the switch control buttons being rendered temporarily inoperative. Relay RZRS, shown in Fig. 1B, is energized over a circuit which may be traced from terminal B, front contacts I9 and 8B of relays INKP and SNKP, back contact 15 of relay LZHS, push button REP, relay RZRS, push button 2N to terminal C. Contacts 19 and are bridged by contacts 8| and 82 of the switch locking relays 2MP and 4MP, respectively, and it is evident, therefore, that relay RZRS may become energized only when the switches are normal or the condition of the switch locking is such that they may be operated to normal. This condition is made manifest by the energization of the route indication lamp REE over a branch of the circuit just traced, as will be clear from the drawings. Relay RZRS is released not only by the operation of key 2N, but is also released when a train enters section IT by the momentary opening of its stick circuit at contacts 86 and 81 as relays I TR and ITP release successively, in a well-known manner. The circuit for the route stick relay L4RS is similar to that for relay RZRS, except that it is independent of the condition of switch I, as is apparent from the drawings.

The call-on stick relays US are stick repeaters of the route relays RS and are controlled by their respective push buttons U in a manner that will be obvious from the drawings. The remaining relays of Fig. 1B are similar in function to one or another of those which have been described, and it is thought that a detailed tracing of their circuits is unnecessary and that their operation will be readily understood from the description of the operation of the apparatus which follows.

In describing the operation of the first form of the apparatus as illustrated in Figs. 1A, 1B, and 1C, it will first be assumed that the apparatus is in the condition shown in the drawings and that a train movement over route cd is to be effected. The operator will first actuate push buttons IR and 3R, thereby energizing relays lRWS and 3RWS and releasing relays INWS and 3NWS, whereupon relays IWR and 3WR will become energized in the reverse direction to release relays I NKP and 3NKP and to operate the the switch machines ISM, 3SM, and 3ASM to reverse. The operator will then actuate push button 2R to energize relay RZI-IS, without necessarily waiting until the switches complete their movement, thereby closing contacts 56 and 63 in the circuit for the signal relay RC2H. When switch I completes its movement and becomes locked reverse, relays IKR and IRKP become energized to close contacts 43, 64, and 59 in the circuit for relay RCZH, and when switches 3 and 3A both complete their movements and become locked reverse, contact 5| closes to complete the circuit for relay RCZH. Relay RCZH then becomes energized, clearing signal RCZ. Relay R2MR releases due to the opening of contact 39 and in turn by opening contact I8 releases relays 2MP and GMP, and the latter relays open the circuits controlled by each of the push buttons IN, IR, 3N, 3R, RZP, and UP so that the inadvertent operation of any of these push buttons will be without effect as long as the signal is at clear. Push button 2L is now ineffective because the circuit it controls is open at contacts J2, and I3; push button 4L is ineffective because the circuit it controls is open at the multiple contacts 83 and 8 3; and push button 4R is ineffective because the circuit it controls is open at contact 85 of relay BNWS. It'is evident, therefore, that the route which has been set up is effectively locked by the clearing of the Signal, so that the signal cannot be interfered with except in a proper manner, namely, by the operation of the release push button 2N. When the train accepts the signal, the operator will actuate button 2N, releasing relays RZI-IS and RCZH to put signal RC2 to stop, thereby reenergizing relay R2MR. When the train vacates section IT, relay 2MP will become energized and when it vacates section 3T, relay 4MP will become energized to release the switch locking.

It will now be assumed that the next train movement to be effected is over route b-e. After lamp REE becomes lighted to indicate the release of the switch locking, the operator will actuate the route button REP, thereby energizing relay RZRS over the branch circuit including contacts iii and 532, and this relay by closing contacts I6 and T! will effect the energization of relays INWS and 3NVVS and the release of relays IRWS and ERWS. Relays IWR and 3WR will then become to the opening of contact 31, and relays 2MP and 4MP will release, the switch control buttons being rendered ineffective both by the opening of the front contacts of these relays and by the opening of the front contacts of relay R2RS included in the circuits for the switch control relays. Buttons iL, 4R, and L lP remain effective to control their respective stick relays, but since switch 3A is locked normal the routes which these buttons govern do not conflict with route b-e. The route button R2P.remains effective to control relay RZRS because it now has a connection to terminal B over contacts I9 and 80.

It will next be assumed tha u the train enters route be and that the call-on signal RB2 is to be cleared to permit a following train to enter the same route. When the first train enters section IT, the opening of contacts 6, 48, and 86 of relay i TR causes relays ITP, RA2H, and RZRS to become deenergized. Relay ITP being slow acting will release after relay R2RS has released. The operator will now actuate button RZP to pick up relay RZRS again, and this relay will be held energized over back contact 8'! of relay iTP, but relay RAZH will remain deen ergized, contact 48 of relay iTR and presumably also contact 49 of relay 2'IR being open. The operator will also actuate button 2111 to pick up relay HUS over contact 88 of relay RZRS, thereby closing front contact 45 in the signal net work to complete the circuit for relay RB2H to clear signal RBZ.

When the second train passes signal RB2, the route set up Will be released automatically in case the first train has already vacated section IT, but in case the second train enters section IT before the first train leaves that section, the relays RZRS and 2US may be released manually by the operation of the release button 2N.

The operations of setting up two of the five possible rou es from left to right through the lay-out have now been traced in detail, and it is believed that the operations of setting up the remaining routes will be readily understood without further explanation. Certain features of the locking of these additional routes, however, will now be pointed out.

Considering route bd, for example, when signal RBI for this route is cleared relay RZMR releases and opens the circuits controlled by push buttons 2L and 4L, and by releasing relays 2MP and 4MP opens the circuits controlled by the switch and route buttons, and since relay 3NWS is released, the circuit controlled by push button 4R is open at contact 85, so that the locking conditions are the same as for route c-d already described in detail. In the case of route c-e, when relay RZMR releases it opens the circuit controlled by push button 2L, but the circuits controlled by the push buttons 4L, 4R, and L41 are not interfered with. In this case, the looking conditions correspond to those for route be, that is, the clearing of signal RC2 for a train movement over route ce does not lock the non-conflicting route a-d.

In the case of route ad, the energization of RAHS opens contacts 89 and 90 to render push buttons 4L and MP ineffective, and the clearing of signal R4 releases relays RAMR and 4MP to open contacts 9| and 92 to render push buttons 3N and 3R ineffective. It will be evident therefore that the clearing of signal R4 does not lock the non-conflicting routes b-e and ce.

The control circuits for governing train movements in the opposite direction through the track layout are generally similar and will be readily understood from the foregoing description. It will be clear that in more complicated layouts several pairs of signal stick relays may be required, and in such cases at least one stick relay of each pair will be interlocked with the opposing relays of one or more different pairs through the medium of the existing approach locking relays. In any case, in accordance with this feature of our invention, the circuits will be so arranged that all of the switch and signal control buttons or levers of the control panel which if operated conflict with the route set up or the signal that has been cleared are rendered iemporarily ineffective without the provision of any special lock-out relays or route networks such as have heretofore been considered necessary in interlocking apparatus of this character.

Another feature of our invention resides in the trafiic direction control provided by the approach locking relay contacts in the circuits for the control relays. Thus for example, if signal R4 is put to stop by releasing RAHS, the push button 4L controlling the opposing slow speed signal LB4 remains inoperative as long as contact 93 of relay RAMR remains open, so that the restoration of the operator's control over button 4L to reverse the direction of traffic is delayed for the time period involved in the operation of relay RAMR. As herein illustrated, this feature is provided for each slow speed signal but is omitted in the case of the high speed signals for the reason that these are provided with track circuit control by the track sections 2T and 4T which are in approach to the opposing signal. In accordance with a further feature of our invention the locking of the control relays is extended to include cases in which the operation of the relays could not interfere with the existing route. This feature is illustrated by contacts I2 and 85 of relay 3NWS in the circuits for relays LZHS and R IHS. These contacts serve to insure that the manipulation of the control buttons occurs in the proper sequence when signal L2 or R4 is to be cleared and also insures that these relays will not be inadvertently energized when the crossover is reversed, in which case they would interfere with the clearing of an opposing signal if allowed to remain energized after the crossover has been restored to normal.

The apparatus of our invention is particularly adapted for remote control by means of a selective communication system of any suitable type, and

to illustrate one manner in which the locking of our control relays may be arranged when our apparatus is remotely controlled we have shown in Fig. 2 the stick relays of Fig. 1B so arranged that they may be controlled by the field station apparatus of a code system of centralized traffic control of a well-known type. To understand the relation between the communication system and our apparatus, it is deemed sufficient to merely point out that the field station portion of the system which is at the location of the track layout of Fig. 10 includes a plurality of delivery relays D, each of which is selectively and momentarily energized at times in response to a code signal trans mitted from a distant control oflice, while at the same time one or more of a group of selecting relays 9, II}, I I, I2 are also energized by certain elements of the code in accordance with the positions of the control levers of one of a plurality of groups of levers located in the control ofiice and with which the operated relay D is identified. To illustrate such control, the energization of the various relays in accordance with the various lever positions is indicated diagrammatically by dotted line connections in the drawings. It is to be understoodthat actually there is but one set of relays 9 to I2 for the three delivery relays ID, ID, and 3D, and that the showing of the relays 9rto I2 is repeated in order to more clearly indicate their control by different groups of levers.

The operation of the second form of the apparatus as shown in Fig. 2 will be explained by assuming that the apparatus of Fig. 1C is in the condition shown in the drawings and that a train movement over route ce is to be effected. The operator will reverse the control lever Sw. 1 of Fig. 2 and also will move the lever Sig. 2 to position R and will then initiate the transmission of the proper code resulting in the momentaryenergization of relays II, I2, and ID. Contacts 94 and 95 therefore close to energize relay IRWS, corresponding to an operation of button IR of Fig. 1B, and contact 96 opens to release relay INWS. At the same time contacts 91 and 98 close to energize relay RZHS, corresponding to an operation of button 2R of Fig. 1B, and when relay ID releases, its back contacts 95 and 99 close to complete the stick circuits for relays iRWS and RIHS. Relay INWS and the indication relay INKR are arranged to be quick in releasing so that the signal circuits controlled by relay RZHS are immediately opened and the energization of this relay is without effect until switch I has completed its movement in response to the energization of relay IRWS, the switch and signal operations being similar to those hereinbefore described.

It is to be noted that in Fig. 2 when the route relay R2RS is energized, relay INWS is steadily energized and also that when relay 2MP is released the closing of its back contact I00 maintains relay INWS or IRWS energized. It is evident, therefore, that these relays cannot be interfered with if relay ID is operated when relay RZRS is energized or relay 2MP is released.

To restore a signal to stop by the apparatus of Fig. 2, a code is transmitted to energize the selected delivery relay such as ID with the corresponding signal lever in its mid-position, and in this case relays l2 and ID are not energized so that the effect of the code is to momentarily open the stick circuits for the signal control relays at contact 99 to release the energized stick relay.

The group of apparatus controlled by relay 2D includes the control relays for switches 3 andSA and signals l with looking circuits similar to those of the similar relays of Fig. 1B, and the operation of these relays will be readily understood from the description of the circuits controlled by relay ID.

While in many cases a route may be set up by sending one code to operate the stick relays controlled by delivery relay ID only, or to operate those controlled by delivery relay 2D only, the operation of stick relays in both groups may be required if neither switch I nor the crossover are in the proper position. Switch l and the crossover may be restored to normal either by sending a single code under control of delivery relay 3D to energize relay RZRS, to thereby energize the two stick relays lNWS and SNW S simultaneously, or by sending two codes in succession to operate relays ID and 2D. In the latter case the order in which the two codes are transmitted is made such that the one which includes the signal control element for the signal that is to be cleared is transmitted last.

One advantage of the route control feature of this form of our invention is that a route involving a whole series of switches may be set up and cleared by the transmission of but one code, thereby avoiding any difficulty that might arise due to the failure of the apparatus to fully receive one or more codes of a series.

The route relays RS and the associated call-on relays US are shown in Fig. 2 controlled by the usual push buttons through the medium of relays 3D and 9 to l2, and since the circuits are otherwise the same as those already described for these relays, their operation will be readily apparent from the drawings. Thus for example, if push button RZP is closed, the operation of relay 3D Will complete a circuit over contacts ill! and 92 to pick up relay RZRS, provided conditions are proper, and relay RZRS will control both the switch l and crossover 3 as may be required so as to set up route b-e, as hereinbefore described while if push button RZP is open, the operation of relay 3D will open contact I83 momentarily to effect the manual release of relay RZRS, to cancel route be.

In illustrating this form of our invention, we have assumed that eachswitch or crossover and the associated pair of opposing signals will be controlled by the same code and by a single relay D. It is obvious, however, that individual codes may be employed, and that relays lNWS and iRWS may, for example, be controlled by one relay D and relays LZI-IS and RZl-IS by another relay D. This is because the arrangement of the apparatus of our invention is such that these relays D may be operated at any time whatsoever and the control relays will respond to their manual control only when conditions are favorable for their operation.

Furthermore, the direct wire control and the code control forms of our invention are inter changeable and both may be employed for controlling different portions of the same track layout. In such cases, for the sake of uniformity, and also in certain cases where no code control is to be used, it may be preferable to employ lever control instead of push button control for those control relays which have direct wire connections to the control panel, in the manner illustrated in Fig. 3. It is to be understood that in the third form of our apparatus, Fig. 3 replaces the portion of Fig. 2 at the left of the line .ry, and it will be readily apparent without tracing the circuits in detail that the switch and signal control relays of Fig. 2 may be operated in accordance with the positions of the switch and signal levers of Fig. 3 by the momentary operation of the push buttons IP or 2P so that these relays will function as in Fig. 1B or 2, and that the operation of the push buttons controlling the route and call-on relays in Fig. 3 is precisely the same as in Fig. 133.

While we have, in the foregoing, illustrated the several forms of the apparatus of our invention by reference to a relatively simple track layout, it will be clear that the same principles can be applied to complicated layouts involving large numbers of trafiic routes and that the system of our invention provides relatively simple and reliable apparatus for safely controlling interlocked railway track switches and signals from a remotely located ofiice or cabin, in such a manner that a train cannot be run over a route different from the intended route due to failure of a switch to respond to an operation of its control means and likewise that our system is so arranged as to provide a maximum degree of protection against interference with the movement of traffic when a signal has been cleared for an approaching train.

Although we have herein shown and described only three forms of apparatus embodying our invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of our invention.

Having thus described our invention, what we claim is:

1. In combination, a traffic route including a railway track switch, a signal at each end of the route to govern the movement of traflic in opposite directions over the route, a switch locking relay for each signal, manually controllable switch control means effective to control the switch only when said locking relays are energized, a signal control relay for each signal, a manually controllable pickup circuit for each signal control relay closed only when the locking' relay for the opposing signal is energized and the signal control relay for the opposing signal is deenergized, a manually controllable stick circuit for each signal control. relay, an energizing circuit for each locking relay closed only when the associated signal control relay is deenergized, and a circuit for clearing each signal controlled in accordance with the position of the track switch and closed only when the associated signal control relay is energized and the signal control relay for the opposing signal is deenergized.

2. In combination, a traffic route including a railway track switch. a signal at each end of the route to govern the movement of traffic in opposite directions over the switch, manually controllable switch control means for controlling the operation of said switch: a signal relay, a signal control relay and a switch locking relay for each signal; an energizing circuit for each signal relay closed only when the associated signal control relay is energized provided said switch agrees as to position with its control means, the signal control relay for the opposing signal is deenergized, and the switch locking relay for the opposing signal is energized; manually operable means for energizing each signal control relay effective only when the locking relay associated with the opposing signal is deenergized, means for energizing each switch control relay only when the associated signal relay is deenergized, and means preventing the operation of the track switch in response to the operation of its control means when either of said locking relays is deenergized.

3. In combination, a trafiic route including a plurality of railway track switches, two opposing signals including one at each end of the route to govern the movement of traffic in opposite directions over the route, manually controllable switch control means for controlling the operation of each switch of the-route; a signal relay, a signal control relay and a switch locking relay for each signal; an energizing circuit for each signal relay closed only when the associated signal control relay is energized and the opposing signal control relay is deenergized provided each switch of the route agrees as to position with its switch control means, an energizing circuit for each locking relay closed only when the associated signal relay is deenergized, a manually controllable circuit for each signal control relay including a front contact of the locking relay for the opposing signal, and switch locking means including front contacts of each of said locking relays for rendering the track switches responsive to the operation of said switch control means.

4. In combination, a traflic route including a railway track switch, a signal at each end of the route to govern the movement of traffic in opposite directions over the route, aswitch locking relay associated with each signal, manually controllable switch control means effective to control the switch only when said switch locking relays are energized, a signal control relay for each signal having a manually controllable energizing circuit, a signal circuit for clearing each signal controlled in accordance with the position of the track switch and including front contacts of the associated signal control relay and back contacts of the opposing signal control relay, means responsive to the closing of said signal circuit for deenergizing the associated switch locking relay, and means for preventing the operation of the opposing signal control relay as long as said switch locking relay remains deenergized.

5. In combination, a traffic route including a railway track switch, a signal at each end of the route to govern the movement of trafiic in opposite directions over the route, a switch locking relay associated with each signal, manually controllable switch control means effective to control the switch only when said locking relays are energized, a signal control relay for each signal having a manually controllable energizing circuit, a signal circuit for clearing each signal controlled in accordance with the position of the track switch and including front contacts of the associated signal control relay and back contacts of the opposing signal control relay, means responsive to the closing of said signal circuit for deenergizing the associated switch locking relay, and means selected in accordance with the position or" the track switch for preventing the operation of the opposing signal control relay as long as said switch locking relay remains deenergized.

6. In combination with a railway track switch, a plurality of trafiic routes over the switch, a signal at each end of each route for governing the movement of traflic in opposite directions over the route, a switch locking relay associated with each signal, manually controllable switch control means effective to control the switch only when said locking relays are energized, a signal control relay for each signal having a manually controllable energizing circuit, a signal circuit for clearing each signal including front contacts of the associated signal control relay and back contacts of an opposing signal control relay selected in accordance with the position of the track switch, means responsive to the closing of any signal circuit for deenergizing the associated switch locking relay, and means selected in accordance with the position of the track switch for preventing the operation of the opposing signal control relay as long as said switch look-- ing relay remains deenergized.

7. In combination, a track layout including a plurality of parallel tracks interconnected by track switches to form different traffic routes, a signal at each end of each route to govern the movement of traflic in opposite directions over the route, a switch locking relay associated with each signal, manually controllable switch control means for each switch, means including said switch locking relays for preventing the operation of each switch when a signal has been cleared to permit a train movement over a route that includes the switch, a manually controllable signal control relay for each end of each route, a signal network comprising a plurality of interconnected signal circuits including one for each route, each of which includes front contacts for the signal control relay for one end of the route, contacts closed in accordance with the positions of the switches of the route, and back contacts of the signal control relay for the opposite end of the route, means responsive to the closing of any signal circuit for deenergizing the associated switch locking relay, and means controlled by said switch locking relay when deenergized for preventing the operation of the signal control relay at the opposite end of the same route.

8. In combination, a track layout including a plurality of parallel tracks interconnected by track switches to form different traffic routes, a signal at each end of each route to govern the movement of traflic in opposite directions over the route, a switch locking relay associated with each signal, a manually controllable signal control relay for each end of each route, a signal circuit for clearing each signal closed in response to the energization of the associated signal control relay and including back contacts of an opposing signal control relay, means responsive to the closing of any signal circuit for deenergizing the associated switch locking relay, means responsive to the deenergization of said switch locking relay for preventing the operation of any switch of the established route, and means controlled in part by said switch locking relay when deenergizecl for preventing the operation of any of said signal control relays for controlling a signal governing an opposing or conflicting route.

9. In combination with. a raiiway track switch, a plurality of traffic routes over the switch, a signal at each end of each route for governing the movement of traffic in opposite directions over the route, a signal control relay for each signal having a manually controllable energizing circuit, a signal circuit for clearing each signal including front contacts of the associated signal control relay and back contacts of an opposing signal control relay selected in accordance with the position of the track switch, a looking relay associated with each signal circuit, means deenergizing each locking relay when the corresponding signal circuit is closed, and means controlled by each said locking relay when deenergized for preventing the operation of the opposing signal control relay.

10. In combination with a railway track switch, a plurality of traflic routes over the switch, a signal at each end of each route for governing the movement of traiiic in opposite directions over the route, a signal control relay for each signal having a manually controllable energizing circuit, a signal circuit for clearing each signal including front contacts of the associated signal control relay and back contacts of an opposing signal control relay selected in accordance with the position of the track switch, a looking relay associated with each signal circuit, means deenergizing each lockingrelay when the corresponding signal circuit is closed, and means controlled by each said locking relay in accordance with the position of the track switch for preventing the operation of the opposing signal control relay as long as said locking relay is deenergized.

11. In combination with a stretch of railway track including a track switch, a signal at each 'end of the stretch for governing the movement of traffic over the stretch, a signal control relay and a locking relay for each signal, a control circuit for each signal including front contacts of the associated signal control relay and back contacts of the signal control relayior the opposing signal, said circuits having a portion in common including contacts controlled in accordance with the position of the track switch, a circuit for each locking relay closed only when the associated signal is at stop, and a circuit for each signal control relay including a manually controllable contact and a contact closed only when the locking relay for the opposing signal is energized.

12. In combination with a railway track layout comprising parallel tracks connected by crossover switches to form different traffic routes, a signal for each direction. for each route, a signal control relay and a locking relay for each direction for each track; a route circuit for each signal, each route circuit including a front contact of the signal control relay at the entrance end of the route which such signal governs and indication contacts controlled by the switches of said crossover, each route circuit also including back contacts of the signal control relay at the exit end of said route; means for clearing each signal when its route circuit is closed and for then releasing the adjacent locking relay, and means controlled by each locking relay when released for preventing the operation of the crossover switches or of the signal control relay at the exit end of the closed route circuit.

13. In combination with a track layout including a plurality of track switches, a locking relay for each switch efiective when deenergized to prevent operation of the switch, a signal for governing traific movements over a particular route through said track layout, a route relay for controlling said signal, a manually controllable energizing circuit for said route relay including a front contact of each said locking relay, each such contact being b-ridged by a contact controlled by the corresponding switch and closed only when the switch position is in accordance with said route, and means controlled by said route relay when energized to operate each of the switches to a position to establish said route .and to clear said signal when said route is established.

14. In combination, a trafiic route including a plurality ofrailway track switches, a switch control relay for each switch of the route, a locking relay for each switch which when deenergized prevents. the operation of its control relay, a route relay, a manually controllable pickup circuit for each route relay closed either when the track switches occupy positions to establish said route or their locking relays are energized, a stick circuit for said route relay, means controlled by said route relay when energized for operating the switch control relays to set up the route, a signal for governing the movement of traffic over the route, a circuit for clearing the signal closed only when said route relay is energized and each switch of the route agrees in position with its switch control relay, and means responsive to the clearing of said signal for releasing each of said locking relays.

15. In combination, a track layout including a plurality of track switches, a normal and a reverse manually operable control contact for each switch, a manually operable route relay, a normal control circuit for each switch including its normal manually operable control contact and in multiple therewith a front contact of said route relay, and a reverse control circuit for each switch including its reverse manually operable control contact and in series therewith a back contact of said route relay.

16. In a centralized traffic control system for railroads, a track layout including a plurality of track switches, a signal for each traffic route through said layout, code control means for each switch and signal for operating the switches to normal or reverse to establish different traiiic routes and for clearing the signal for the established routes in response to different code signals, and other code controlled means for simultaneously operating a plurality of said switches in response to a single code signal to establish a particular trafiic route through said layout and for clearing a signal governing traffic movements over said route when said route has been established by the operation of the track switches.

1'7. Ina centralized traffic control system for railroads, a track layout comprising parallel tracks connected by crossover switches to form non-conflicting trafiic routes when said switches are normal and a traflic route which includes both tracks when said switches are reversed, a signal for each route, a remote controlled relay for each end of each track for clearing the adjacent signal, an energizing circuit for each signal closed in response to the energization of the corresponding remote controlled relay when the route which such signal governs is established by the track switches, but only if the remote controlled relay for the opposing signal for the same route is deenergized, a locking relay for each end of each track which when deenergized prevents the operation of the track switches, means responsive to the clearing of a signal for releasing the adjacent locking relay, means controlled by that looking relay which is released when a signal for a route including both tracks is cleared Ill plurality of track switches, a route relay for each of. a plurality of routes through said layout, means controlled by each route relay when energized to operate the track switches as required to establish the corresponding route, a switch locking relay for each switch energized only under conditions favorable for operation of the switch, and means preventing the energization of the route relay for any route when a locking relay for a switch of that route is deenergized 'and the position of said-switch is not in accordance with the route.

19. In combination, a track layout including a plurality of track switches, a route relay for each of a plurality of routes through said layout, means controlled byeach route relay when energized to operate the track switches as required to establish the corresponding route, a switch locking relay for each switch energized only under conditions favorable for operation of the switch, a manually operable contact for each route relay for controlling such relay, and means controlled jointly 'by each track switch of the corresponding route and by its switch locking relay for at times preventing the energization of such route relay in response to the operation of its manually operable contact.

20. In combination, a track layout including a plurality of track switches, a route relay for each of a plurality of routes through said layout, means controlled by each route relay when energized to operate the track switches as required to establish the corresponding route, a switch locking relay for each switch energized only under conditions favorable for operation of the switch, a manually operable contact for each route relay for at times energizing said route relay, and indication means associated with said contact and controlled jointly by each track switch of the corresponding route and by its switch locking relay for indicating when conditions are favorable for setting up said route by the energization of said route relay.

21. In combination, a track layout including a plurality of track switches, a route relay for a particular route through .said layout, means controlled by said route relay when energized to operate the track switches as required to establish said route, a switch locking relay for each switch energized only under conditions favorable for the operation of the switch, a manually operable contact for at times energizing said 'relay, and indication means associated with said contact and controlled jointly by each track switch of the route and by its switch locking relay for indicating when conditions are favorable for setting up said route by the energization of said route relay.

22. .In a centralized traflic control system for railroads, a track layout incuding one or more track switches adapted to form different trafllc routes, signals for governing traiiic movements in each direction over said routes, a locking relay for each signal which when deenergized prevents operation of any switch of the corresponding route, each such locking relay becoming deenergized when such signal iscleared, a signal control relay for each signal, an energizing circuit for each signal including in series, a front contact of the associated signal control relay, con- :tacts controlled by one 'or more track switches in accordance with the route which such signal governs, a back contact of the opposing signal control relay, and a front contact of the locking relay for the opposing signal for the same route; and a circuit for each signal control relay including .a manually control-led contact and a front contact of the locking relay for such opposing signal.

'23. In a centralized trafiic control system for railroads, a track layout including one or more track switches adapted to form different 'trafllc routes, signals for governing trafiic movements in each direction over said routes, a locking relay for-each signal which when deenergized prevents operation of any switch of the corresponding route, each such locking relay becoming deenergized when such signal is cleared, a signal control relay for each signal, an energizing circuit for each signal including in series, a front contact of the associated signal control relay, contacts controlled by one or more track switches in accordance with the route which such signal governs, a back contact of the opposing signal control relay, and a front contact of. the locking relay for the opposing signal for the same route; a circuit for each signal control relay including a manually controlled contact, and means preventing the energization of each signal control relay when any opposing signal has been cleared, comprising a front contact of the locking relay for each such opposing signal in the circuit for each signal control .relay.

RONALD A. MCCANN. HENRY S. YOUNG. 

